JPS641485Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a position detector for detecting the position of a valve body in an exhaust gas recirculation control valve equipped with a pressure chamber.

Conventionally, there has been a type of exhaust gas recirculation control valve with a position detector as shown in FIG.

In the figure, 1 is a low-pressure side case having a nipple 1a that communicates with a negative pressure source (not shown), 2 is a high-pressure side housing paired with this case, and a valve seat 8 is provided in the middle part. It has a passage 2a. A shaft 3 is supported by the housing 2 via a bearing 11, and has a valve 3a seated on the valve seat 8 at its lower end. Reference numeral 5 denotes a diaphragm whose outer peripheral portion is held between the case 1 and the housing 2, and whose central portion is sandwiched between the high-pressure side plate plate 4 and the low-pressure side spring plate 6, and is attached to the shaft 3 together with them. is fastened to the upper end of the 7 is a spring arranged to press the spring tray 6 downward;
Reference numerals 9 and 10 are a low pressure chamber and a high pressure chamber separated by the diaphragm 5. A position detector 14 is provided to detect the movement of the shaft 3, and has a rod 14a. And this rod 1
4a is lightly pressed by a spring inside the position detector so that it always moves in contact with the shaft 3 of the control valve. Reference numeral 12 denotes a position detector fixing plate that is integrated with the case 1 by welding, copper brazing, etc., and the position detector 14 is controlled by screws 15 on this fixing plate 12 together with an O-ring 13 for keeping airtight. It is fixed to the case 1 of the valve.

Next, its operation will be explained.

When the force due to the pressure difference between the pressure chambers 9 and 10 exceeds the spring force of the spring 7, the diaphragm 5 is displaced and rises together with the shaft 3 against the spring force of the spring 7, opening the valve 3a from the valve seat 8. do. Note that when the above pressure difference decreases, the valve 3a closes due to the spring force of the spring 7. This displacement of the shaft 3 is detected as the displacement of the rod 14a of the position detector 14, which operates in constant contact with the shaft 3.

As described above, the conventional exhaust gas recirculation control valve with a position detector uses the control valve case 1, fixing plate 12, airtight O-ring 13, fixing screw 15, and many other parts to detect the detector. is installed, the dimensional accuracy after assembly deteriorates and initial variations are large. Furthermore, there is also a problem in ensuring reliability against loosening of the airtight O-ring and the fixing screw.

This invention was made in order to eliminate the drawbacks of the conventional ones as mentioned above, and it was made in case 1 of the control valve.
By integrally molding the nipple 1a and the position detector 14, the number of parts when installing the position detector is reduced, and an inexpensive exhaust gas recirculation control valve with a position detector with high accuracy and reliability is provided. It is intended to.

An embodiment of this invention will be described below with reference to the drawings. In FIG. 2, reference numeral 1 denotes a low-pressure side case that is integrally molded with the position detector 14 together with a nipple 1a that communicates with a negative pressure source (not shown). and the position detector 14 are integrally formed by molding. 16 is a fixing ring for fastening the low-pressure side case 1 and the high-pressure side housing 2 via the diaphragm 5. Note that the other configurations and operations are the same as those shown in FIG. 1 above, so explanations will be omitted. Further, in the above embodiment, the fixing ring 16 is used to fasten the low-pressure side case 1 and the high-pressure side housing 2, but the fastening may be performed using screws 17 or the like as shown in FIG. 3.

As described above, the exhaust gas recirculation control valve with a position detector according to the present invention has a low pressure side case 1 and a nipple 1.
Since a and the position detector are integrally molded, the dimensional error when connecting the position detector and control valve is much smaller than that of conventional products.
Initial variations in characteristics are reduced and the number of parts is reduced. In addition, since there is no O-ring 13 for maintaining airtightness or screws 15 for fixing the position detector 14 that were conventionally used, problems such as maintaining airtightness or loosening of screws are eliminated, and the number of component parts is small, resulting in improved accuracy and reliability. This has the effect of producing an inexpensive product with significantly improved properties.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view showing a conventional exhaust gas recirculation control valve with a position detector, FIG. FIG. 7 is a partial cross-sectional view showing another embodiment of the invention. In the figure, 1 is a low pressure side case, 2 is a high pressure side housing, 3 is a shaft, 5 is a diaphragm, 7 is a spring, 9 is a low pressure chamber, 10 is a high pressure chamber, and 14 is a position detector. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] In an exhaust gas recirculation control valve equipped with a position detector and a pressure chamber, the case of the position detector that detects the movement of the valve body, the case for forming the control valve's pressure chamber, and the pressure chamber communication nipple are integrated by molding. An exhaust gas recirculation control valve characterized by comprising: